Thu, 12 May 2005
Well, I've had at least one email asking about the X Config for my Triple head setup.. So, I thought I'd chuck it up here, explaining the relevant bits.
Ok, to start with, you need to make sure your ServerFlags section turns on Xinerama:
Then, you need to create some Device sections for each head - with a dual head nvidia card, you can use the Screen option to distinguish between the outputs - I'm not sure if this is specific to the nvidia driver. With multiple cards, you must specify the BusID option - you can find out what the correct value is for your card by running 'X -scanbus' and checking the output (which on my system gets sent to /var/log/XFree86.0.log).
Here's what I use (First two are on a Dual head AGP card, the third is the PCI card):
Next up, you need to create some relevant Screen sections to go with each of the above. Childs play - this is so far, all bog standard X stuff. I have:
Finally, You need to add each Screen to your ServerLayout section, to create a virtual definition of how your physical displays are set up. I have the following (note that the logical order of my displays in relation to the devices defined above is '2-0-1' from left to right)
And that's it. X is clever enough to do the rest for you. I'm currently using XFree86 on Debian unstable, but I'd imagine the X.org setup would be somewhat similar.
And just for reference, this is the Device section I used before going to 3 heads, which shows how to use TwinView:
You can use TwinView when you have more that two displays, if you're only using one nvidia card. (this is how Jon Oxer is still using TwinView)